Researchers at Lawrence Livermore National Laboratory (LLNL) believe that 3D printed materials filled with sodium carbonate could be used to capture CO2 emissions. To demonstrate their hypothesis, the researchers have already developed a small capsule version of the technology.

Is there anything baking soda can’t do? The wonder salt, otherwise known as sodium bicarbonate, seems to be a million things at a time: an essential ingredient in cakes, an effective form of pest control, and a toothpaste ingredient, amongst other things. Now, according to a group of California researchers, baking soda could even save the planet.

On April 22, 177 members of the United Nations Framework Convention on Climate Change (UNFCCC) signed the Paris Agreement, a treaty which proposes the necessity of a maximum 2 degree increase in global temperatures. Many believe that the only way to achieve this goal is through carbon capture and storage (CCS), a proposed form of technology that would capture CO2 from chimneys and flue pipes before it gets into the atmosphere.

Despite widespread agreement that CCS is essential to achieving the 2 degree goal, efforts to create such technology have been limited—the UK even scrapped a proposed £1 billion grant to encourage development of the technology in November 2015. “Nobody can see us keeping temperatures increases below 1.5 degrees without these technologies,” Dr Oliver Geden, a member of the German Institute for International and Security Affairs, told the BBC. “Yet there hasn't been any debate about this technology and it doesn't exist at scale.”

Because of the projected high costs of developing CCS, some scientists are looking at experimental ways of creating the technology on a budget. A group of LLNL researchers, for example, believe that 3D printed polymers and baking soda could be used to create affordable CO2-capturing technology.

To verify its hypothesis, the scientists created a number of microcapsules consisting of a liquid solution of sodium carbonate (soda ash), surrounded by a permeable polymer shell. The capsules, which look like tiny blue balls, are placed in an aqueous solution, and turn yellowish brown when in contact with CO2. This happens as the sodium carbonate and CO2 react to form sodium bicarbonate: baking soda. Although the microcapsules are small, 3D printing could be used to recreate the technology on a larger scale, where it could be fitted above chimneys.

According to the researchers, not only would the baking soda technology be safer than monoethanolamine, which some scientists are trying to harness in CCS technology, it would also be cheaper and more efficient: “Like all the commercial CO2 schemes we have today, the goal for large scale implementation is taking many tonnes of gas from a power plant and finding geological features deep underground where we can inject that CO2 and it will stay indefinitely,” said Joshua Stolaroff, an environmental researcher at Livermore. “Microcapsule solvents like we've developed can do that, we hope, at lower energy use and capital cost, about 40% lower than the current methods.”

To recover the carbon, users of the innovative CCS solution would have to heat up the baking soda solution, which would itself be beneficial, as it would produce a purer and thus more valuable form of the gas. The researchers are, however, taking their project one step at a time, as they can currently only produce around 1kg of capsules per day: “We think in the US, our regulations will promote carbon capture and storage at a commercial scale around 2022, and we look at technologies that can be ready around that time,” said Stolaroff. “We hope that around that time frame the benefits of our technologies will be developed and known.”

By using 3D printing, the researchers hope to be able to create larger versions of the technology, using the same principles but in a non-capsule form. These 3D printed materials could be used directly within power stations to capture CO2. “You can think of it as CO2 capture fabric,” said engineer Du Nguyen. “What this is made of is a silicone material and inside of that are lots of little bits of sodium carbonate. You can almost think of it as a CO2 sponge.”

According to the LLNL researchers, the technology could also have uses outside of power stations, with places like breweries potentially using the technology to recover carbon for economic reasons.

“We think there is great promise that baking soda might save the world,” Stolaroff concluded, only half joking.